Extended Data Fig. 8: Repeatability measurements.

Each iteration is a separate cycle of a bus re-mounted to a qubit package, cooled down and measured. Exception is iteration 8, where the device was not disassembled and reassembled from iteration 7, but only thermally cycled. Different markers represent different qubit samples and packages. Together, iterations 1 and 6 are the ones during which the main experiment data were collected. We have obtained ‘clean’ Sideband oscillations with Ω/2π ≈ 5 MHz in all iterations but iterations 7 and 8; there, we achieved only Ω/2π ≈ 4.5 MHz before observing high-power effects. a, Relaxation times (solid red), Ramsey (solid blue), and echo decay times (open blue). b, Qubit-bus dispersive shift χ (green) and bus lifetime (purple) across each iteration.